<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <button id="btn">加载index.js</button>
    <script>
       const btn = document.getElementById("btn")
        btn.onclick= async function(){
            // 测试发现加了await，就会先执行index.js,再打印okk
            // 说明import会返回promise实例，因为await只会等promise实例
         await import ("./index.js")
            console.log("okk")
        }
    </script>
</body>
</html>